The invention relates to a method of treating a male for impotence, namely a male's inability to achieve or maintain a penile erection of adequate rigidity for sexual intercourse. The invention also relates to apparatus for irradiating an object with monochromatic light, preferably a laser beam, which apparatus is particularly useful in such method.
The penis consists of two longitudinal cylindrical bodies called the corpora cavernosa. These bodies are composed of sponge-like tissue that contains tiny vascular spaces (cavernous sinuses) surrounded by smooth muscle. A third cylinder is the urethra, a tube that carries the urine and the ejaculate. Blood flows to the penis via two very small arteries that come from the aorta. During erection, blood is pumped into the penis under great pressure, and a series of valves trap the blood in the penis to maintain the erection.
The sequence of events that initiate an erection includes relaxation of the sinusoid muscle, which results in a decrease of resistance and an increase in blood flow. The events that lead to this smooth muscle relaxation are controlled by biochemical substances which are released from the nerve endings after sexual stimulation. These substances include, among others, the endothelium-derived relaxing factor (EDRF), also known as nitric oxide (NO). NO has been found to act as a neurotransmitter causing smooth muscle relaxation in the urogenital tract and seems to be the final mediator of penile erection. Penile erection is mediated by nitric oxide via cyclic guanosine monophosphate. Any medication or process which will mimic these mechanisms will enhance an erection.
Following are the main types of impotence and their causes:
psychogenic impotence, caused by impulses from the brain which inhibit the erectile process; PA1 neurogenic impotence, secondary to nervous system disorders; PA1 arteriogenic impotence, secondary to disease of the arteries which supply blood to the penis; PA1 hormonal impotence, caused by a deficiency of androgens and loss of sexual interest and erections; PA1 impotence caused by a deficiency of nitric oxide (NO) production in the corpora cavernosa of the penis, which has been implicated in erectile dysfunction; PA1 venogenic impotence, caused by abnormal venous channels of communication, producing an inability to maintain an erection; and PA1 erectile tissue disfunction impotence, secondary to fibrosis, trauma, diabetes, tumor infiltration and others. PA1 vacuum constrictor devices; however these may be cumbersome to use and may cause pain and/or premature loss of penile tumescence/rigidity. PA1 transdermal administration of vasoactive drugs; however these are usually ineffective. PA1 transurethal administration of vasoactive drugs; however these may cause pain and insufficient erection. PA1 intracavernous injection of vasoactive agents; however these are frequently accompanied by side effects including hematomas, pain, formation of fibrotic nodules within the corpora cavernosa, penile curvature and priapism. PA1 penile prosthesis implantation; however this involves irreversible destruction of corpora cavernosa vessels, and possible complications including infection, erosion of a component of a prosthesis, and mechanical failure of prosthesis components. PA1 sildenafil (e.g., Viagra, the recently introduced drug) which prevents degradation of the cyclic guanosine monophosphate and thus enhances erections; however, this may be accompanied by serious, possibly fatal, side effects.
Currently the following methods are used in the treatment of impotence i.e., to enable, or to improve the ability of, a male to achieve or maintain a penile erection of adequate rigidity for sexual intercourse: